This invention relates to a novel protein food product and method of making the same.
A substantial effort in the food industry has been directed towards the production of meat analogs, or products which resemble meat in flavor and texture, but are derived from other protein sources, such as vegetable protein. A great deal of research has been centered in the conversion of vegetable protein sources such as defatted oilseed meals into meat simulating products. This research has, therefore, been directed towards two objectives, including the reproduction of the textural or organoleptic properties of meat, as well as the minimization or masking of the "bean-like" flavors that are derived from vegetable protein sources such as soybeans, once the textural properties are reproduced.
Reproduction of the textural properties of real meat has been successfully achieved by extruding a ground, solvent extracted oilseed meal such as defatted soybean meal under conditions of elevated temperature, pressure and moisture to achieve an expanded, textured product. Such products and methods for their production are essentially described in U.S. Pat. Nos. 3,496,858 and 3,488,770. The extruded products, either prior to drying or after drying and upon rehydration, are resilient in texture, with the masticatory properties of the muscle tissue of meat.
While the art has generally been successful in the simulation of the textural properties of meat, so that a food of realistic textural characteristics can be produced nevertheless, it has not been entirely successful in masking or eliminating the undesirable bean-like flavors which are characteristic of vegetable protein sources such as soybeans. Depending on the formulation in which the expanded food product is used, it may create a marginal palatability situation or one where the economic advantages of employing a more readily available protein source is offset by a decrease in palatability. This, therefore, requires critical and careful control of flavorants for food products of this type to minimize this problem. Another approach has been an attempt to extract these expanded products with hot water in an attempt to leach out the undesirable flavors, such as described in U.S. Pat. No. 3,142,571. Such an additional step in producing a product such as a pet food adds to the cost involved, and thus is economically undesirable. It may, furthermore, be unsuccessful in achieving a substantial increase in palatability by removal of objectionable flavors, and, thus still require stringent control of added flavorants for the masking of bean-like flavors.
The present invention is, therefore, directed towards the production of a novel protein food product which has the desirable flavor of real meat, while retaining the economic and functional advantages of employing a vegetable protein source. This novel food piece comprises an extruded mixture of a meat source and a vegetable protein source such as oilseed meal, oilseed protein isolate or similar material. The resultant product has a texture substantially identical to the extruded soy products described above, and yet the flavor of the meat source is retained. The novel protein product of this invention may be employed in human food such as stews, clam chowders, or the like or canned pet foods; since it is sufficiently stable to retain its integrity after retort processing. It can also be dried after extrusion, to provide a dry food product which upon rehydration with water, simulates the textural and masticatory properties of meat, but with the added advantage of having the flavor of a cooked meat piece.
Fresh animal meat and oilseed meals have heretofore been combined for extrusion although with a significant proportion of farinaceous materials, as described in U.S. Pat. No. 3,447,929. The disadvantages of such a product include a non-resilient texture with the inability to survive abrasive action such as chewing along with an inherent structural instability in a hot aqueous medium. Thus, although the flavor of such a product is excellent, it lacks the desired structural characteristics of an extruded oilseed material.